1. Field of the Invention
The present invention relates to a broadcast receiving apparatus configured to receive broadcast waves of digital and analog television broadcasting services or terrestrial and satellite broadcasting services, and also relates to a method for controlling a broadcast receiving apparatus. In particular, when a broadcast receiving apparatus includes plural tuners simultaneously receiving plural programs, the present invention can transmit the contents of an emergency warning broadcast to a viewer/listener and minimize an interruption by such a specific broadcast when a user is viewing or recording a television program.
2. Description of the Related Art
Television viewers can enjoy different types of broadcasting services, including analog terrestrial broadcasting, analog broadcasting satellite (BS) broadcasting, cable broadcasting, digital terrestrial broadcasting, digital BS broadcasting, and digital communication satellite (CS) broadcasting.
Recent television receivers, set-top boxes (STBs), and digital video recorders (DVRs) are configured to receive two or more types of broadcasting services. Thus, television viewers can use plural tuners for receiving different broadcast programs. For example, a user can record a CS broadcast program while viewing a digital terrestrial broadcast program. If a television receiver is equipped with two digital terrestrial broadcast tuners, a user can simultaneously record two different programs in the same time slot.
Since 1985, an emergency warning system (EWS) has been managed in Japan for the purpose of immediately informing the public of an occurrence of serious disaster or earthquake through television broadcasting or radio broadcasting. According to the emergency warning system, a broadcast station transmits an emergency warning broadcast signal and each receiver (e.g., television or radio) receives the emergency warning broadcast signal and performs a predetermined operation to let a viewer or listener recognize the occurrence of an emergency warning.
Japan Broadcasting Corporation (NHK) and other commercial broadcasting companies employ such an emergency warning system. In particular, NHK can transmit an emergency warning broadcast signal using all available broadcasting media, including digital terrestrial broadcasting, analog terrestrial broadcasting, and digital BS broadcasting. Therefore, each viewer/listener can receive an emergency warning broadcast signal through any broadcast receiver in an on state.
However, if a broadcast receiver is in an off state or in a stand-by mode, the receiver can receive no emergency warning broadcast program. Therefore, important information contained in an emergency warning may not be transmitted to some users.
To solve the above-mentioned drawback, as discussed in Japanese Patent Application Laid-Open No. 2004-023591, a display device can be forcibly activated if in an off state to receive a control signal from a television broadcast receiving apparatus (tuner) and transmit the contents of an emergency broadcast, to a viewer/listener.
According to the technique discussed in Japanese Patent Application Laid-Open No. 2004-023591, a television broadcast receiving apparatus is equipped with a power source section capable of supplying electric power to a display device in an off state when an emergency warning is raised.
Furthermore, the technique discussed in Japanese Patent Application Laid-Open No. 2004-023591 includes processing for determining whether an installation location of the broadcast receiver is in a target area of the emergency broadcast with reference to installation location information of the broadcast receiver and region identification information involved in emergency information. If it is determined that the broadcast receiver is in the target area, electric power is supplied to the display device. If it is determined that the broadcast receiver is out of the target area, the emergency broadcast is not displayed on the display device.
If a broadcast receiver is equipped with a single tuner, the technique discussed in Japanese Patent Application Laid-Open No. 2004-023591 can be directly applied to the broadcast receiver. However, as described above, recent television receivers, STBs, and DVRs are equipped with plural tuners.
A user will be confused if the technique discussed in Japanese Patent Application Laid-Open No. 2004-023591 is applied to a broadcast receiving apparatus equipped with plural tuners. More specifically, an emergency warning broadcast can be received by each tuner. Each tuner independently operates to inform an occurrence of an emergency warning broadcast. Thus, in a situation that different television programs are displayed in a multi-screen display pattern on a display device, if a user simultaneously receives the same contents of an emergency warning broadcast through different (e.g., digital and analog, or terrestrial and BS) broadcast channels, the user may be unable to appropriately confirm and act in response to the emergency information.
In this respect, as discussed in Japanese Patent Application Laid-Open No. 2005-159779, a broadcast receiving apparatus can include plural reception systems each including a channel selection circuit (tuner) and a decoding circuit. One reception system can be used to continuously receive a reception signal for recording, while the other reception system can be used to select an emergency broadcast channel and display the contents of the emergency broadcast on a display device.
However, the technique discussed in Japanese Patent Application Laid-Open No. 2005-159779 cannot be directly employed if plural channels can simultaneously receive the same emergency warning broadcast. If plural channels simultaneously receive the same emergency warning broadcast, user's viewing or recording a broadcast program may be undesirably interrupted.
In this case, a user cannot properly view or record a desired program. The techniques disclosed in Japanese Patent Application Laid-Open No. 2004-023591 and Japanese Patent Application Laid-Open No. 2005-159779 cannot overcome these drawbacks.